The invention was developed as a batch process/apparatus for treating an aqueous slurry of hog manure from a hog-raising facility. It will be described in connection with that specific feedstock. However it is anticipated that the process/apparatus may find application in connection with other feedstocks as well, such as poultry manure, dairy whey and municipal effluent.
These feedstocks are generally anaerobic (low in oxygen) and contain naturally occurring bacteria. The bacteria multiply rapidly with increasing temperature, when oxygenated. They will digest the organic matter in the waste, over time, to produce substantially clarified, metabolic water. The odor of the metabolic water is much improved when compared to the original feedstock.
The feedstocks also contain solids which are non-digestible by the bacteria and which should be separated from the slurry and removed. For example, hog waste commonly contains barley hulls and fibrous matter, which remain immune to digestion by the bacteria. It is desirable to separate and remove the non-digestible solids to enhance the digestion process and to produce relatively clean water which can be re-used.